Project Summary The proposal entitled 'Elucidating the essential role of the evolutionarily conserved IME4 mRNA methyltransferase in metazoan development' is in response to PAR 12-006 Academic Research Enhancement Award (Parent R15). The objective of this project is to elucidate the mechanism by which IME4 affects metazoan development, generating data for rational design to investigate its function in mammalian systems in the context of evolutionary conservation. IME4 (Inducer of Meiosis #4, first identified in budding yeast), is an N6methyltransferase of adenosine residues in messenger RNA without altering the genetic code, i.e., it is a non-editing RNA modification. IME4 is evolutionarily conserved from budding yeast to human beings, yet its biological role remains elusive. Recent publications have mapped the mRNA methylome in mice and human cells showing overlapping categories of this enzyme's putative targets, highlighting its evolutionarily conserved role. However, in vivo whole-organism studies of the biological role of this enzyme are lacking. My previous work in S. cerevisiae showed that this enzyme is key in budding yeast's decision to become a gamete. It appears that IME4's role in yeast is exclusively during meiosis and it is not an essential gene for asexual life. However, in higher organisms where it has been studied, IME4 is an essential gene. In D.melanogaster, our published and preliminary data show it is required for embryo and larval development with important roles later in adult reproduction. Given its high degree of evolutionary conservation, we hypothesize that IME4 is required for essential functions in higher vertebrates, including humans. To test this hypothesis, we will employ biochemical (protein interactions), genetic, and cell biology (microscopy) approaches in D.melanogaster and D. rerio, two evolutionarily distant metazoan species, an invertebrate and a vertebrate respectively, predicting a high degree of functional conservation common to both that will be likely conserved in mammals. Approaches and techniques will provide excellent venues to train students in developing critical thinking skills and gain first-hand experience in the design and technology involved in biological experimentation. This project will generate important data that will impact the field of RNA modifications in developmental biology.